Electrical measuring instrument.



T. W. VARLBY.

BLBGTMCAL MBASURING INSTRUMEN'L.

APPLICATION FILED 001210, 1h07 T. W. VARLEY.

ELECTRICAL MEASURING INSTRUMENT.

APPLICATION FILED 00T.I0.1`107. 1,182,890.

5 SHEETS-SHEET 2 Patented Mar. 23, 1915.

T. W. VARLBX.

ELECTRICAL MEASURING INSTRUMENT.

Appmonxox FILED conm, wm.

1,1 32,890. Patented 13.11.23, 19m.

n??? ULEB (BCS. if), i907.

Patented Mar` 23, i915.

APPLMATION FILED OC'L'. 1U, LM'

Patented Mar. 23, 1915.

5 SHEETS-SHEET 5.

Hw m T 1? A T". m. :Si i ma v WWAV I. 115 l M U L J .El

msaeeo.

sirens ssrn" THOMAS W'. VAB-LEY, 0F NEW YORK, Y., ASSIGNOR TO WSTNGHQUSE ELECTRIC EJNUFACTURING COMPANY, CQRPGRATIGN 0F NSYLVANIA. I

ELECTRICAL IYEASUEIN` INSTRUMENT.

Specieaton of Letters Patent.

f Patented Mar. 23, 1315;.

Application led October 16, i967. Serial No. 393,867.

stantially constant magnetic field, caused by either an electro-magnet or a permanent magnet as preferred, in combination ``.Wi tl1 stationary and movable coils so disposed that a current passing through the stationh ary coil. will shift. or distort the lines of force of' the constant magnetic field in such manner as to canseatorque on the movable fcoil, the unctioaof thev stationary coil being simply to shift the, lines of force in the constant magnetic field andnot necessarily tov create the magnetic field itself, asin th ordinarv electric dynamometer. f I livill hereinafter describe, inl connection with the accompanying drawings, a structure embodying my improvements, the fealires thereof being more .particularly pointed out hereinafter in the claims.

In the drawings Figure 1 is a side eleve..- tion, partly in section of' a structure de signedto be used as an integrating watt meter. Fig'. is a top plan view ofone form of' magnet. Fig. 3 is a plan View, on an env larged scale, and partly in section, of the parts shown in Fig. 4. Fig. 4 is a side el'eration, partly in section, showing the details of the scheme of commutator brushes on an enlarged scale. Fig. 5 is a side elevation of one form of core support. Fig. 6 is a plan View', partly broken away, showing one means of adjusting the position of the core support. Fig. 7 is a plan view of a modification showing the use of an annular magnet without pole pieces, parts bein removed. Fig. 8 is a diagrammatic view of the connections. Fig. 9 is 'an elevation, on an enlarged scale, and partly in section and partly broken away, showing a detail of the cup support. Fig. 10 is a diagranxm-tic View showing the windings of them'ova le coil and the Ycornrnutator connections.

Similar numerals of reference indicate similar parts throughout the several views. l represents a substantially constant mngnet, here shown in the form o a permanent horse shoe magnet. '2 representsa pole piece provided with a central aperture 8, prefern ably 1n the form of an ellipse. The magnet lmay be provided with upwardly project-A ing teeth or shoulders 4 overfwhich slots 5 in polepiece 2 are adapted to it in order to provide a good magnetic connection. lf desired, magnet l may be made of a plurality of magnets or leminreplaced side by side (not shown).

6 represents a substantially rectangular.

plateof any suitable material, such as brass, adapted to be fastened to pole piece 2 to form Va snpport for other parts. Plate 6- is out away centrally as at 7 and is provided lwith a-shoulder 8 extending along 'each end ofthe plate. A box or core support 9, comprising a top plate 10, centrally apertured to register with opening 7 in plate Y6, sideA members 11, 11 and bottom plate'12 is adapted to be adj ustably secured on plate 6: Top plate 10 is provided with openings 13 .and 14 to permit of adjustment of position and is adapted tmb'ewclamped to Aplate 6 by set' screws 15. Top plate 10 is further provided with `a circumferential groove 16. Side members 11, 1l extend downwardly from top plate 9 on each side of pole piece 2. A'

of non-magnetic material, supportQ being in turn held t0 bottom plate l2 of box or core support- 9 by a screw 27. A cup 28, preferably of aluminum, is supported from a shaftiQQ having one bearingon a jewel 30 in core 9.5'anl another in bracket 3l supported on box or cors su port 9, the lower bearing of the shaft 29 being above the center ofavity of the moving element, thus giving stabilit to the armature and lessen-j ing the side thrust of shaft 29 on the vtop bearing in bracket 3l. Shaft 29 also carries a commutator cylinder 32 and a gear wheel Y 33 adapted `to mesh with a suiteblegear wheel (not shown) for driving the register ing mechanism 34. Brushes 35 are supported by standards 20, one end of each hrus being clanip'e to one of the standards ZO i. a screw 36 and the other being attached t' spring 37 fastened to another of the standv ards 2() by a thread Standards 2G cut away on their inner sides at 39 to give a ner adjustment to the brushes.

As showniin Fig. 8, 40 is a source of' electrical ener here shown as a direct current ,f generator.l '41 1s a resistor representing the load shunt. 42 is an adjustable resistor, adapted to adjust the load currentthrough the armature and, in conjunction 'with moving contact i3, to vary the amount of potential current passing through the an mature to compensate for initial friction of moving .pai-ts. lll represents the stationary or Alie'ld coil wound to forni a four pole field corresponding Ato the armature winding. Coil, 4A is supported in any conm ,venient way' on the inside face of aperture 3 coaxiall'y with the armature winding, or it may be mounted on the' box or Acore support 9, as desired, and is preferably in the ,form of a distributed Winding. 45 is an adjustable resistor in the potential circuit. 16 represents the load.

The arma/ture Winding is placed on the lcup 28 and 'is shown diagranimatically in Fig. 10 in connection with the cornmutator. lAs illustrated, the armature winding is .adapted to form a four pole, two circuit Winding, utilizing an even number of cornmutator bars and armature coils. ln the ordinary form of four pole,l two circuit Winding, all the commutator bars are connected successively to the armature coils and, Where the pairs of poles are even in number, an odd number of coils and4 bars.

are used. In the armature Winding shown in Fig. l0, one halt of the comniutator confV nections are omitted, as shown, the commutator bars being ldiametrically cross nected instead, thus enabling the armature to be wound with an even number of coils and bars. Otherwise the armature winding is well known and does not need further description to those skilled in the art.

In F ig. 3 four brushes are shown, opposite brushes being electrically connected and considered as one, which arrangement is shown diagrammatically in Fig. 8.

In the operation of the device, the mov able coil or armature is in a balanced condition with respect to the magnetic Geld but becomes unbalanced when currenttraverses the stationary coil, this unbalancing being a function of the current the stati nary coil, thetorque on the moving coil varying as the product of the current in the rnow ing coil and the current in thestationary coil, the current in the moving coil vary y as the current to the load and the current through the stationery coil varying as the or stationv etardation or `tegrating watt meter. 7g

ly providing a single pole piece having a central aperture a lor the armature and. formeel which is ly sli and ivliic, in value and time, follows more exactly the changes of the current strength in the fixer; coihno breaks be ingY ni, de in the sides, thickness of the sites being adji l desired The rnagnetic eld is also aneoted by external influences. The aperture in the pole piece eg "referahlj mace not a circle to pen stinent, for example, or finding a magnetic i v initof an, tile magnetic een for moving coil or tarmasn Mounting the core, armature and parts, on a sinffie support enables the Whole ,to be adjusted as one with reference to the magnetic center without altering their relative positions. Making the brushes ad justable cirouinter-entiallgv enables the proper commutation point to ber found,

laeh brush is preferably made of s, Sexi 'ole 'flat strip of silver, liet side to the comn inutatcr, fastened at one and. in any suitable manner so as to maite electrical Contact and at the other end by spring and thread, one vbrush standard of each. pair being in sulated to forni the electrical connection to ne load shunt, as illustrated herein. The spring puts the proper tension on the brush' Elfi? and the thread prevents the spring from twisting the flat strip under varyinn'tension the spring. This constructioi'ivpermits use or a ligrt and flexible brush Witl1 low inertia, insures a fixed. point ot Contact '52.5 on the connuntater, allows toe brush t" dom to follow suraiie of the commi. w tor redness the liability o the brush to leave the commutator because of commutaf tor inequalities orbecause of jarringr l'" ,errerwith temperature changes. The cnn 28 Civ being fof aluminum, `he currents set up in the cup will also vary with temperature changes. By a proper proportioning of the amount of copper and manganin used in the coils and resistor specified, theresultant efv feet of temperature changes can be made substantially zero, thus rendering the instrument independent ot' temperature changes For example. the resistance of the stationary coil may be made thirty per cent. of the field circuit risistor and the resistor' of the resistance fill seventy per cent. thereof, While the resistance or the moving coil may be made seventy per cent. of the armature circuit resistance and the resistance of resistance 42 thirty per cent. thereof.

Let K represent` the temperature coei- The torque causing rotation will, therefore,fchange as ri .aart t) X1 was, t) a 1 rmt-t)21mm-tor,

Since K is small, being .905k per degree centigrado. rise in temperature, .2lK2(t1- t2): is inappreciable and sabstantially negligibie. Therefore', the torqueprodueing rotation isv HKM-0) orsubstantially the same as the torque producing retardation. In other words, as the torque falls with rise in temperature so will. the drag, each countcracting the other, the speed of rotation remaining constant for varyingr temperatures( other conditions not 'being c anged. f'

I do not restrict myself to any of the details of structure or arrangement of parts shown and described as it is obvious that mav be aried without departing from the spirit of the vention.

While the invention illustrated as applied to an integr that it adapted to use in connection with indicating watt metc 3 vvel with volt meters and simmetria and with either direct or alte fing rirrents.

Yi t I claim and oesire to secure by VLett attent is:

l, lin electrical measuring instrument rising relatively movable coils.y and re` sisters having resistaIme-temperature cocfieients different from those of the coils, the ratios of the res stances of the coils to those of the resistors respectively in circuit therewith being in substantially inverse re lation to cach other.

An elcctricai measuring instrument comprising a substantially constant magnet havingan elliptical aperture between its poles a rotatable armature located in said a; re and having a commutator cylinder, :mda support that is adjustable With respect to thc magnet and carries the said armature..

3. An chu'tricai measuring instrument comprising a substantially constant magnet Watt meter it is clear ta or cylinder, and a. support therefor that is carried by the aforesaid support and is adjustable with respect thereto.'

L An electrical measuring 'instrument coriprising a substantially constant magnethaving an -elliptical aperture between its poles, a. core located in said aperture, a r0- tatable armature surrounding said core and having a, commutator cylinder, a support that is adjustable with respect to the magnet and carries the said core and armature, brushes bearing ou the commutator cylinder, anda support for the brushes that is carried by and isr adjustable with respect to the aforesaid support. l

5. An .electrical measuring instrument comprising a magnet having an unbroken magnetic circuit and an elliptical aperture between its poles, a core located in said aperture a movable coil surrounding said core, an a support that is adjustable with respect to the magnet and carries the core v and coil.

(i. An electrical measurin instrument comprising relatively' movab e coils, reslstors respectively 1n ,clrcuit therewlth, a

yconducting member driven by the relative movement of the said coils, and a magnet adjacent to the conductingmember, the coils and conducting member being composed of materials having similar resistance-tempera- A ture coeicicnts, and the resistors being coniposed of materials having res1stance7temios aneciemprrziture cocliicirnts, and the resisi t rs being composed ot' .materials having reduire-temper a I.u re coeiicieuts differing th'ucifroin, 'und the ratios of the resistances oilthc coils to those of thcrresistors respecviiely in circuit therewith being such that that the forward and retariling torques of tbe instrinnont' vary substantially1 proportionately with changes of temperature.

fi. An electrical measuring instrument comprising relf,.tiveiv movable coils, resistors respectively in t .uit therewith, a conducting member driven by the relative movement of the coils, and a magnet adjacent to the n'iosfable member, the said coils and movable member having appreciable resistance-temperature coetiicicnts, and the stois having substantially negligible re- J ance-temperature coeilicients, and the ratios of the resstances ot the coils to those of the resistors respectively in circuit therewith being in subsiantialiy inverse relation to each other.

9. An electric-ai measuring instrument comprising relatively movable coils, resistors respectively in circuit tl'ierewith, a conducting member driven by the relative movement of the coils, and magnet adjacent to the movable member, the said coils :iniii Zal) movable member ,having appreciable `tancetemperature coetbcients, and the 4tors haring substan' ly negligible re- .ncetmnpcrnture cocliifionts, and the ratances et the coils to those respectively in circuit there- 'li that the forward and reci the instrument vary subrwnticnat.iy with changes of Eli iin) if i bein;

measuring instrument rely movable coils, and reely in' circuit therewith, the vv o he coils to those r squirt-ly in circuit therei mbsisntially inverse relation te' tzlci. itidi i i ."xn eiectrical comprising i magia? neasuri ng instrument ,saving a substantially and in the direction of its longer elliptical opening between its poles, a core, a movable coil surrounding said core, said core and coil being located in the opening in the magnettand means for adjusting said core and coil transversely of said opening axis.

12. An electrical measuring instrument comprising a magnet having a substantially elliptical opening between its poles, a core, a movable coil surrounding said core, said core and coil being located in the opening in the magnet, and means for adjusting said core and coil transversely of said opening.

' 13. An electrical measuring instrument comprising-relatively movable coils, resistors respectively in circuit therewith, a conducting member driven by the relative movement of the coils, and a magnet adjacent to the conducting member, the coils and conducting member having different resistance-temperature coefficients from the resistors, and the ratios of the resistances of the coils to those of the resistors respectively in circuit therewith being in substantially inverse relation to each other.

14. An electrical measuring instrument comprising relatively movable coils, resis tors respectively in circuit therewith, a conducting member driven by Vthe relative movement of the coils, and a magnet adjacent to the conducting member, the coils and conducting member having different re sistance-temperature coeilicients from the resistors, and the ratios of the resistances of the coils to those of the resistors respectively in circuit therewith being such that the forward and retarding torques of the instruments vary substantially proportionately with changes in temperature,

15. An electrical measuring instrument comprising relatively movable coils and resistors respectively in circuit therewith having substantially negligible resistance-temperature coefficients, the ratios of the resistences of the coils to those of the resistors respectively in circuit therewith being in substantially inverse relation to each other.

In testimony whereof I have hereunto signed my name in the presence of two subscribing witnesses.

. THOMAS W. VARLEY. lVitnesses:

. ROBERT W. ASHLEY,

Chausson S. ASHLEY.

Corrections n Letters Patent No. 1,132,890.

It is hereby certified that in Letters Patent No. 41,132,890, granted March 23, 1915, upon the application of-Thomas W. Varley, of New York, N. Y., for an improvement in Electrical Measuring Instruments, errors appear in the printed slnecification requiring correction as follows: Page 3, line 11, for the word resistor, both occurrences, read resistance; same pagg-13,' line 12, for the word resistance read resistor; simiepage, line 16, fo'r the syllables sistance read sz'sor; page 4, line 49, for thc word rcsistuncc read rcs-islmicas; and that the said Letters Patent should be reed with'these corrections therein that the same may conform to the record of the case in the Patent Ofice.

Signed and sealerl this 1st day of June, A. D., 1915.

. T. NEWTON,

Acting Commissioner of Patents. 

